Like adaptor for current collectors for lights electric appliances or the

ABSTRACT

An adaptor for electric current consuming devices such as lights, electrical appliances or the like, which is shiftable and fixable on a current distributor rail, containing at least one protective conductor which projects at the top (front) and before fastening the adaptor, can be brought into contact with a rail protective conductor, and locking parts which are mechanically movable in opposite directions to lateral walls of the rail, and are connectable by clamping and/or spring-operated manner to fastening portions of the current distributor rail, as well as at least two electrical conductors which, in depdendence upon locking parts, are movable in opposite directions to rail lateral walls to bring them into contact with the electrical currentcarrying conductors of the current distributor rail.

United States Patent 1 Hesse Sept. 4, 1973 [76] Inventor: Kurt Hesse, 38 Waterfohr, 4920 Lemgo-Lippe, Germany [22] Filed: June 25, 1971 [21] Appl. No.: 156,820

[30] Foreign Application Priority Data June 30, 1970 Austria A 5894/70 Mar. 27,1971 Germany P 21 14 911.1

[52] US. Cl 339/21 R [51] Int. Cl H0lr 9/00 [58] Field of Search 339/14 R, 14 P, 21 R, 339/21 J, 22 R, 22 B [56] References Cited UNITED STATES PATENTS 3,686,614 8/1972 Hyrylainen 339/21 R 3,688,240 8/1972 Routh et al. 339/21 R 3,613,045 10/1971 Routh et a]. 339/21 R 3,081,442 3/1963 Platz 339/14 3,611,252 10/1971 Fremont 339/21 R 3,496,518 2/1970 Neumann et a1 339/21 R FOREIGN PATENTS OR APPLICATIONS 40,644 12/1968 Finland 339/21 R 1,911,315 7/1970 Germany 339/21 R Primary ExaminerMarvin A. Champion Assistant Examiner-Robert A. I-Iafer Attorney-Steinberg & Blake [5 7 ABSTRACT An adaptor for electric current consuming devices such as lights, electrical appliances or the like, which is shiftable and fixable on a current distributor rail, containing at least one protective conductor which projects at the top (front) and before fastening the adaptor, can be brought into contact with a rail protective conductor, and locking parts which are mechanically movable in opposite directions to lateral walls of the rail, and are connectable by clamping and/or spring-operated manner to fastening portions of the current distributor rail, as well as at least two electrical conductors which, in depdendence upon locking parts, are movable in opposite directions to rail lateral walls to bring them into contact with the electrical current-carrying conductors of the current distributor rail.

10 Claims, 22 Drawing Figures United States Patent 1 [111 3,757,273 Hesse 1 Sept. 4, 1973 PATENIEDSEP 4% 3.757. 273

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PATENIEB EP' ADAPTOR FOR CURRENT COLLECTORS, FOR LIGHTS, ELECTRIC APPLIANCES OR THE LIKE The invention relates to an adaptor for current collectors for lights, electrical appliances or the like, which is shiftable on a current distributor rail; it can be fixed in each position, and is equipped with two electric conductors and at least one protective conductor.

Adaptors of this type have become known in various designs. The deficiency of the known devices lies in the intricate operation and partly inadequate electrical safety. Furthermore, the known adaptors are of limited current carrying capacity.

It is the object of the invention to produce an adaptor for collectors which is constructed simply, economically, strongly, and compactly. The adaptor must almost be able to be completely accommodated (up to a connection part for the collectors) inside a current distributor rail.

A further object of the invention is the provision of high electrical safety and high current rating.

A further object of the invention is the provision of easy mechanical and electrical locking and unlocking on a current distributor rail.

Furthermore, the adaptor has to ensure correct polarisation with a current distributor rail.

A further object of the invention is seen in the avoidance of arc formation between the contacts of the adaptor and the current distributor rail, upon breaking the current closure.

Moreover, the adaptor has to be designed as a feeding, bridging and supplying adaptor.

In accordance with the present invention there is provided an adaptor for electric current consuming devices such as lights, electrical appliances or the like, which is shiftable and fixable on a current distributor rail, containing at least one protective conductor which projects at the top (front) and before fastening the adaptor, can be brought into contact with a rail protective conductor, and locking parts which are mechanically movable in opposite directions to lateral walls of the rail, and are connectable by clamping and/or in spring-operated manner to fastening portions of the current distributor rail, as well as the least two electrical conductors which, in dependence upon locking parts, are movable in opposite directions to rail lateral walls to bring them into contact with the electrical current-carrying conductors of the current distributor rail.

In a preferred embodiment the locking parts and the electrical conductors are rectilinearly shiftable at an angle, preferably at right angles, to the axis of symmetry of the rail cross-section, by means of a common gear mechanism, such as a toothed wheel or a frictional wheel gear mechanism. This gear mechanism has for example, one toothed wheel and two toothed segments which mesh with the latter, and are designed as manually operated parts, and which can be turned through a limited range.

Catches are arranged about the shafts which form the axes of rotation of the gear mechanism parts for changing the rotary movement of the gear mechanism into a rectilinear shifting movement of the locking parts and of the electrical conductors. The catches co-operate with pressure or push surfaces which are provided on the locking parts and on the shifting bodies which hold the electrical conductors.

In a further feature of the invention the adaptor is provided with conductors which are rapidly movable for contact closure and breaking, and which in each case are held in the respective position by a flexible member.

Each conductor is fastened to a pivotably mounted contact lever, and the contact lever is held by a helical spring in the respective position, or is brought into the latter.

With two facing contact levers there is in each case a pressure body which is fastened to a shaft which serves for the shifting movement of locking parts which are movable in opposite directions; when the shaft is rotated through approximately this pressure body produces an outward pressure between its two points of application, so that upon passage of the dead centre point formed by the bearing point of the contact lever, the spring pivots the contact lever with conductor suddenly into the contact or break position. In the contact position the spring holes the conductors in contact.

In accordance with a further feature of the invention, the adaptor is characterised by a current conductor with a contact part having locking parts fixing the adaptor in the current distributor rail according to position, lever-shaped and movable to and fro in opposite directions in the current distributor rail breadth, in each case by an outer contact part contact-closable with a conductor of the current distributor rail, mounted in the adaptor housing and a current conductor with a current carrying part mounted inside the adaptor housing after the contact closure between adaptor contact part and rail current conductor, formed with a delay and suddenly contacting an inner contact bridge, which bridge is designed to be rapidly liftable from the current carrying part upon'releasing the adaptor before the contact breakage between current distributor rail conductor and outer adaptor contact part.

In a specific embodiment, the lever-shaped current conductor is mounted by means of a fastening medium with one end pivotable in the adaptor housing, and has at its other end a plate-shaped contact part and is equipped between the contact part and fastening medium with a shaped contact bridge with the end adjacent to the contact part freely moving and self-flexible as well as by a spring arranged between the contact bridge and fastening medium and held in the switch-off position.

Pressure surfaces on a shaft co-ordinate with the facing lever-shaped current conductors as well as the two facing contact bridges which simultaneously carries a locking part for mechanically locking the adaptor, which surfaces act one after the other for the electrical contact closure, whereby the contact bridge, immediately upon contact between contact part and rail current conductor, is suddenly connected to the current carrying part for the current flow or previously rapidly raised.

Exemplified embodiments of the invention are represented in the accompanying drawings, in which:

FIG. 1 shows a perspective view of a current distributor rail, into which an adaptor can be inserted so as to be shiftable and fixable according to position;

FIG. 2 shows a perspective view of an adaptor;

FIG. 3 shows a cross-section through the adaptor and the current distributor rail in the inserted position of the adaptor;

FIG. 4 shows a longitudinal section through the adaptor along the section line I I in FIG. 3; F

FIG. 5 shows a longitudinal section through the same adaptor along the section line II II in FIG. 4;

FIG. 6 shows a longitudinal section through the same adaptor along the section line III .III in FIG. 4; and

FIG. 7 shows a longitudinal section through the same adaptor along the section line IV IV in FIG. 4;

FIG. 8 shows a top plan view of a further embodiment of an adaptor along the section line V V in FIG. 10, with jerkily movable conductors and an earthing plate which has flexible earthing bars;

FIG. 9 shows a bottom plan-view in half-section of the same adaptor along the section line VI VI in FIG. 10, with locking parts which are shiftable by a toothed wheel of a shaft which is operable by hand;

FIG. 10 shows a longitudinal section through the same adaptor along the section line VIII VIII in FIG. 8;

FIG. 11 shows a cross-section through the same adaptor inserted in a current distributor rail, along the section line VII VII in FIG. 10; 7

FIG. 12 shows a perspective view of an adaptor arranged on a current distributor rail, in a further embodiment;

FIG. 13 shows a bottom view of the same adaptor, partly in section, with facing current conductors in the switched-off position,

FIG. 14 shows a cross-section through the same adaptor along the section line IX IX in FIG. 13, with a protection conductor connection part;

FIG. 15 shows a longitudinal section through the same adaptor having current connectors separated, connected to the electrical conductors of the current distributor rail, but still carrying no current, and with partly mechanical locking;

FIG. 16 shows a longitudinal section through the same adaptor having mechanical and electrical locking;

FIG. 17 shows a longitudinal section through the same adaptor in the still locked state, but again with currentless current conductors;

FIG. 18 shows a side view of an adaptor half of a further adaptor, partly in section;

FIG. 19 shows a top plan view of the adaptor of FIG. 18, partly in section, with swingable contact parts and switch shaft locking device;

FIG. 20 shows a horizontal longitudinal section through the same adaptor;

FIG. 21 shows a horizontal longitudinal section through one partial region of the adaptor with a slide block which is operable by the switch shaft, and connects the contact part to the current-carrying part, in switched-on and switched-off position;

FIG. 22 shows a horizontal longitudinal section through a partial region of the adaptor with modified on and off switching connection between contact part and current-carrying part.

An adaptor of the invention 10, 29, 80 and 105 (connection and fastening body) for collectors, such as lights, electrical appliances or the like, is designed to be shiftable and fixable according to position on a current distributor rail 11; the adaptor 10, 29, 80 and 105 can be shifted over the entire length of each rail 11, and be fixed at any desired point.

The adaptor 10, 29, 80 and 105 and the rail 11 are in each case equipped with at least two electrical conductors 12, 43, 83, 106 or 13, and at least one protection (earthing) conductor 14, 70, 100, 121 or 15.

The protection conductor 14, 70, and 121 of the adaptor 80, 10, 29, is projecting at the top side (front side), and before fastening the adaptor inside the current distributor rail 11, is closable with the rail protection coneuctor 15. The adaptor 10, 29, 80 and 105 possesses locking parts 18, 50, 81 and which are mechanically movable in opposite directions to rail lateral walls 16, and are connectable by clamping or in spring-operated manner to fastening receptacles 17 (grooves) of the current distributor rail 11, and in dependence upon the locking parts 18, 50, 81 and 110, or their shifting, if need be, electrical conductors 12, 43, 83 and 106 can be contact-closed with the electrical conductors 13 of the current distributor rail 11, but with movement-dependent delay in relation to these locking parts. 7

The adaptor 10, according to FIGS. 1 to 7, possesses a housing 19 of a rectangular shape which is boxshaped, can be closed with a top-sided cover 19a, and is formed from two identical housing halves.

The locking parts 19 and the electrical conductors 12 are, by means of a common gear mechanism 20, provided rectilinearly shiftable at an angle, preferably at right angles to the axis of symmetry of the rail crosssection.

The gear mechanism 20 has, on rotatable shafts 21a, 22a and 23a 'a central toothed wheel 21 and two toothed segments 22 and 23 which mesh with the latter, andare provided as manually operated parts for fixing the adaptor.

On each bar-shaped or tab-shaped locking part 18, which is shiftable in a guide of the housing 19, and is movable out of the housing 19 from an opening 24 (slot) of the housing lateral walls, is provided a clamp 18a which co-operates with a surface 25 of a fastening receptacle l7.

About the axis of rotation 21a of the central toothed wheel 21 of the gear mechanism 20 there is arranged as a pressure means for each locking part 18, a catch several, shifting bodies 30 which have in each case at least two contact studs as electrical conductors 12, which are arranged inversely shiftable in guides of the housing 19, and can be moved outwards from openings 31, such as slots or the like, in the housing lateral walls.

ies 30 arranged one behind the other in longitudinal direction of the housing are partly movable (compare FIG. 7) out of the housing in opposite directions.

The shifting movement of the shifting bodies 30 takes place via the toothed wheel 21 and the two toothed segments 22 and 23, which are designed to be twistable through a limited rotation angle range. Each toothed segment 22 and 23 and the toothed wheel 21, on the shaft 22a, 23a and 21a, for each adjacent shifting body 30, has a catch 33 (tooth-shaped projection), as a pressure organ, which catch co-operates with push surfaces 32 of the shifting bodies.

Each shaft 21a, 22a and 23a possesses two facing projections 33, which engage in a recess 34 of the shifting body 30, which recess is formed in each shifting body lateral region, and forms the push surfaces 32.

The two catches 33 of each gear mechanism shaft 21a to 23a are rotatable through an angle of approximately 90, and thereby these catches 33, upon the movement of the shifting body 30 for the electrical contact closure, engage in the recesses 34 only after a certain rotation of the toothed segments 22 and 23 and the toothed wheel 21, so that a delay in the movement of the shifting bodies 30 in relation to the locking parts 18, which are shifted directly upon twisting, occurs.

The toothed segments 22 and 23 are provided to be rotatable by a handle 36, which enters through a slot 35 or the like of the housing floor, which slot limits the extent of rotation of the toothed segments 22 and 23. The handle is detachable and projects outwards from the housing 19.

The protective conductor 14 of the adaptor 10 is formed from a contact pin which is held under automatic tension, and is held shiftable in a stationary connection part 37 for a detachably connectable line in extension of the height of the housing.

The protective line is not fastened here to the movable contact pin 14, but to the immovable connection part 37 in the receptacle, which is mounted in the housing 19.

The two identical housing halves are held together by fastening screws 38. The cover 19a has bearing points for the gear mechanism shafts 21a to 23a, and is fastened detachably to the housing 19 by means of screws 39 or the like.

The adaptor 10, is made of plastics material, and has at the bottom a connection body 40 for lights, light sockets, electrical appliances or the like. 7

The current distributor rail 11 is equipped in both lateral regions with two electrical conductors 13 arranged one on top of the other, and in the upper region with two protective conductors 15 held beside each other. The current distributor rail 11, which is designed U- shaped in cross-section, has a plastics profile strengthened with metal, and shows an acceptance space which is adapted to the cross-section of the adaptor.

The arrangement of the electrical conductors 12 in both rail lateral regions and the provision of two protective conductors 15 as well as the arrangement of the conductors 12 and 14 in the adaptor 10, provides the rail 11 and the adaptor 10 with two separate circuits or one three-phase circuit. v

In the unfastened state of the adaptor 10, its electrical condcutors 12 and the two locking parts 18 extend inside the cross-section extension; the operation parts 36 form a detent in one end region of the curved slot 35 of the housing 19. The adaptor 10 to be fastened tothe current distributor rail 11 is led into the acceptance space of the rail 11, whereby its top-sided protection conductors 14 are immediately connected to the rail protective conductors 15 by contacts. Now the two operation parts 36 are pivoted in the same direction of rotation in the slots 35, so that the two toothed segments 22 and 23 are turned; the toothed wheel 21 meshing with them is also given a rotating movement, which produces a shifting of the two locking parts 18 outwards in opposite directions, whilst the catches 26 with their catch surfaces 26a act upon the pressure surfaces 27a of the locking parts 18. The catch surfaces 26a, which are arranged eccentrically about the axis of rotation of the shaft, produce, during rotation of the toothed wheel through approximately a shifting of the locking parts 18 outwards, and consequently a fastening (locking) of the adaptor 10 inside the current distributor rail 11.

After the two locking parts 18, through a partial rotation of the gear mechanism 20, have already carried out a certain shifting move, the shifting of the electrical conductors 12 outwards takes place the electroconductors 12 are moved outwardswith delay. The toothshaped catches 33 of the three gear mechanism shafts 21a, to 23a engage in the recesses 34 of the shifting bodies 30, which recesses have push surfaces 32, nd push these bodies upon further rotation of the shaft. The conductors 12 move the locking parts 18, and when the shifting of the locking part ends, the conductors 12 are brought into the outward shifted position. If the locking of the adaptor 10 has taken place in the rail, there must exist contact closure between the conductors 12 and 13.

To detach the adaptor 10, the two operation parts 36 are rotated in the opposite direction, and the gear mechanism parts 21 to 23 receive an inverse rotating movement.

In this rotating movement, the catches 26 with their catch surfaces 26b act upon the pressure surfaces 27b of the locking parts 18, for the purpose of shifting the locking parts 18 into the adaptor 10. Simultaneously, the catches 33, which are situated in the recesses 34, take with them the shifting bodies 30, and the conductors 12 are likewise moved into the adaptor 10 upon shifting the locking part. As soon as the catches 33 emerge from the recesses 34 of the shifting bodies 30, the shifting of the conductors is terminated, and only the two locking parts 18 are moved still further inwards. If the operation parts 36 strike the slot end regions, the movement of the locking parts 18 is also terminated.

The adaptor 29 represented in FIGS. 8 to 11, in a further embodiment, is like the adaptor of FIGS. 2 to 7, designed to be shiftable, and fixed in position on a current distributor rail 11 (compare FIGS. 1, 3 and 11); this adaptor 29 has a housing 42 which is formed from two halves which are identical and are held together by screws 38. The (housing) is, however, modified in its construction in relation to the housing 19.

This adaptor 29 is equipped with electrical conductors 43 which are for contact closure with the conductors 13 of the current distributor rail 11 and are rapidly movable into the outer contact position, whereby each conductor 43 is held by a flexible tension organ 44 in the out-of-contact position and in the contact position, and is movable by a pressure body 45 which acts upon the tension organ 44.

Each conductor 43 is pivotably mounted with a contact lever 46 about a bearing point 47 for moving into the contact and outer contact position; the conductor 43 is plate-shaped in design, and is designed as a single part production piece with the contact lever 46.

The tension organ 44 which is formed from a helical spring rubber or plastic band or a flexible bar acts with its two ends on both sides of the bearing point 47 at one end on the contact lever 46 and at the other end on one point of the housing. The working point 48 of the tension organ 44 on the contact lever 46 lies between conductor 43 and bearing point 47, and the other working point 49 of the tension organ 44 extends at a spacing to the bearing point 47, the bearing point (switch shaft 51, which serves for the shifting movement of locking parts 50, is in each case associated with two conductors 43 which are movable in'opposite directions for contact closure.

The pressure body 45 for two adjacent tension organs 44 possesses two facing pressure surfaces 45a, which are provided in each case at a spacing to the shaft axis which is greater than the spacing of the bearing points 47 of facing contact levers 46 to the shaft axis is maintained at.

On each switch shaft 51 are two pressure bodies 45, which are arranged on top of one another at a spacing, and which in each case act as switch organs for two facing conductors 43. The four conductors 43 are arranged in a common longitudinal region of the adaptor 29 and are operated together by a shaft 51.

At a spacing to each end region,.seen in longitudinal direction, of the adaptor 29, is arranged a group of four conductors 43, two of which are provided facing one another and on top of one another.

In order to give the tension organs 44 a guide during the influence of pressure and consequently their position alteration, each pressure body 45 is equipped in the region of the facing pressure surfaces 45a, with a groove-like edge 45b, in which the tension organ 44 is inserted and guided.

The bearing point 47 for each contact lever 46 is formed from a channel-like cavity of a contact carrier 53 which is fastened to the housing 42. A contact carrier 53 is provided for two conductors 43 which are arranged in each case in a common longitudinal region of the adaptor 29, so tht in the two longitudinal regions of the housing 42 there are in each case fixed detachably on the inside by screws 54 or the like, two contact carriers 53 arranged one on top of the other.

The contact carriers 53 which face one another in pairs are plate-like in design, and are fastened to the insides of the housing halves by screws 54 which are provided at a spacing to the length-bisecting ends of the adaptor 29, and which in each case engage in an insertion thread 55 ofthe housing halves.

Each contact carrier 53 has at its two ends a bearing part 56 which is curved towards the facing contact carrier 53, and is forked, and which possesses a channellike cavity; into these cavities of the forked bearing ports 56 is inserted one end region of a contact lever 46, and it is pivotably mounted in these. In order to fix the contact lever 46 in the pivotal axis direction, it engages with end-sided bars 57 in recesses which are provided on the insides of each forked bearing part 56.

Each contact carrier 53, in its two end regions at a spacing to the bearing parts 56 inside its length extension has a bar 58 which is arranged between these bearing parts, is bent down towards the facing contact carrier 53, and holds the tension organ 44 at one end.

The tension spring 44 which at one end hooks in a recess which is connected to the bent down conductors 43, and at the other end is fastened to the bar 58, extends in a recess 59 of the contact lever 46, which recess runs in longitudinal direction of the lever in the free space formed by the forked bearing part 56, so that the tension organ 44 within the forked contact lever 46 and the bearing part 56 can be moved out via the contact lever bearing point 47.

A flexible clamp 60 is fastened by the four screws 54 which hold the contact carrier 53 on the housing, to each contact carrier 53, for each conductor 43 of one housing side. Each clamp 60, between itself and a channel-like cavity 61 of the contact carrier 53, carries in clamping and detachable manner an electrical lead 62.

Each contact carrier 53, up to its contact points (bearing point 47 and channel-like cavities 61) is covered by an insulation layer of plastics material.

The two shafts 51, arranged rotatably in the housing 42 at a spacing to each other in longitudinal direction of the housing, are equipped with atoothed wheel 63 which extends below the pressure bodies 45, which meshes with two facing toothed parts 64 of the two adjacent locking parts 50 which are shiftable in opposite directions; when the shaft 51 is twisted, the locking parts 50 co-ordinated with one shaft 51 are shifted for the purpose of fastening the adaptor in the current distributor rail 11. Each locking part 50 engages with two lateral grooves 65 across a guide bar 66 which is arranged on the housing 42, so that the locking parts 50 are guided in their shifting movement on both sides.

For the limitation of the shifting movement of the locking parts 50 into the fastening position (movement taking place outwards), the grooves 65 are closed at their inside ends, whereby the shifting movement is limited in the event of the butting of the closed groove ends against the bars 66.

The two shafts 51 are designed to be rotatable by a handle 67', through at least 90, and can be moved to and fro between two marks 0 and I, which are arranged on the underside of the housing and are formed by elevations or cavities. 0 indicates the out-ofcontact position (the conductors 43 and the locking parts 50 extend inside the housing 42), and I states the contact position (the conductor 43 and the locking.

parts 50 have been moved outwards) (compare FIG. 9). For centering the housing halves to be connected to each other each housing half engages with an inside centering cone 68 in a corresponding recess of the adjacent housing half.

In the upper region of the adaptor 29.is fixed inside grooves 69 of the two housing halves, an earthing plate 71, which is equipped at the ends with two earthing bars 70 which are arranged beside one another at a spacing and flexibly held; this earthing plate 71 is inserted with its two longitudinal edge regions in one groove 69 of the two housing halves in each case, which groove is formed on one partial region of the housing length, and is fixed in these grooves 69 after the connecting of the housing halves by the screws 38. The two earthing bars 70 provided in the two end regions of the earthing plate 71 are, on this plate 71, bent at right angles upwards with respect to the plane of the plate, and stand beside one another at a spacing which corresponds to the spacing of the protective conductors of the current distributor rail 11. The earthing bars 70 are provided on individual upward-bent flexible plate tongues 71a, so that they are held flexibly by the plate tongues 71a which are movable downwards. r

The earthing plate 71 is equipped with at least one earthing screw 72. The housing 42 has at its two front sides one removable closing part 73 which, in the event of use of the adaptor 29 as a current feeding appliance, releases one cable introduction aperture. In the region of this closing part 73 cable collars (not represented) are provided on the inside of the housing 42, which served as tension relief for the electrical leads introduced.

On each closing part 73 the contact levers lie adjacent in the outer contact position, and are consequently held against one another at a necessary safety spacing.

Furthermore, the housing 42 possesses in its upper cover region a central working aperture 74, which is limited by the earthing plate 71, for the connection of electrical leads, and in its lower floor region a central insertion thread 75 for a light fixture.

In order to obtain safety in the event of fatigue or destruction of the tension organs 44, and thereby ensure a rapid moving-back of the contact levers 46 with conductors 43 in to the outer contact position, there is between each contact lever 64 and the housing wall, a pressure element 76, such as a pressure spring.

Upon insertion of the adaptor 29 into the current distributor rail 11, each shaft 51 has been rotated into the zero position, and the conductors 43 as well as the locking parts 50 extend within the breadth of the adaptor. If the adaptor 29 is inserted into the acceptance space of the U-shaped rail 11, there exists equally contact closure between the earthing bars 70 and the rail earthing conductors 15. The earthing bars 70 push against the earthing conductors l5, and are pressed with their spring tongues 71a in the direction of the housing 42. Through the flexible action of the tongues 71a, the earthing bars 70 are continually held under pressure on the earthing conductors 15 of the rail 11.

There is now rotation of the two shafts 51 through 90 whereby a shifting of the locking parts 50 outwards via the toothed wheel 63 and the toothings 64 meshing with its takes place the locking parts 50 engage in the fastening receptacles 17 of the current distributor rail 11, and are clamped in them with their clamping surfaces 50a, so that the adaptor 29 is connected firmly, but detachably to the rail 11.

Upon rotating the shaft, there follows rotation of the pressure bodies 45 through 90; The pressure bodies 45 press against the facing tension organs 44, and shift the tension organ regions between the two working points 48 and 49 outwards. The contact levers 46 with the conductors 43 retain their outer contact position over a certain twisting region of the pressure bodies 45; immediately after exceeding th dead-centre point (bearing point 47) of the tension organ movement, the contact levers 46 with the conductors 43 are suddenly pivoted outwards, and produce a contact closure with the rail 13. The pivoting of the conductors 43 into the contact position takes place only when the locking parts 50 have accomplished their entire shifting path. The movement of the conductors 43 into the contact position immediately after exceeding the dead-centre point, and a rapid movement of the conductors is then achieved through the working points 48 and 49 of the tension organs 44 and the bearing point 47 of the contact levers 46.

The twisted pressure bodies 45, by butting of their pressure surfaces 45a against the tension organs 44, secure the conductors 43 on the rail conductors 13 under compressive stress. If the adaptor 29 has to be released, the shaft is rotated backwards and the locking parts 50 are shifted again into the adaptor housing 42. The conductors 43 thereby again retain their contact position for so long, until the tension organs 44 have been moved back with their regions deformed by the pressure bodies 45 via the dead-centre point (bearing point 47 and then fly back suddenly through the tractive force of the organs 44 into the outer contact position (into the housing 42). With this adaptor 29 there is en sured in a simple and safe manner a rapid moving of the conductors for the contact closure and for the out-ofcontact position, so that arcs are precluded, and the adaptor 29 exhibits great electrical safety.

The earthing bars are provided on the outer edge regions of the tongue 71a, and the tongues show a rooflike design in longitudinal direction, so that upon shifting the adaptor 29 held by the locking parts 50 on the rail 11, heads of fastening screws of the rail 11 in the region of the tongues 71a, press the tongues 71a in the direction of the housing 42, and consequently the tongues 71a present no impediment.

The current distributor rail 11 of FIG. 11 corresponds in its basic construction to the rail 11 of FIGS. 1 and 3. A modification of the rail 11 has, however, been undertaken regarding the fixing of the conductors.

In the case of the current distributor rail 11 according to FIG. 11, the two lateral conductors 13 are embedded in a plastics carrier moulding 77, which is inserted in an acceptance space 78 of the plastics jacket 16 from the rail acceptance space. Furthermore, the conductors 13 exhibit a rectangular shape of cross section, and are held standing up on edge in the carrier profile 77.

The plastics layer 16 surrounds a metal rail 79 as a carrying rail part.

Through the design of the adaptor 29, the latter shows in relation to the adaptor 10 a smaller size of cross-section, more especially a smaller width, so that the current distributor rail 11 is also narrower (compare FIG. 11).

The adaptor 10 and 29, on both sides of its lengthbisecting ends, is equipped with fixing grooves 41, which co-operate with non-symmetrical fixing bars provided on the front of each rail 11, and ensure a safe location of an adaptor 10 and 29 in the abutment region of two current distributor rails 11, for the electrical connection of the two rails 11 by the adaptor 10 and 29. Through the diagonally-facing fixing bars provided on one side of both rail ends, the adaptor 10 and 29, for the purpose of electrical connection, can be inserted in the abutment region of the current distributor rails 11 which butt together, whereby a safe transfer of the energy from one rail 11 to the other is ensured.

The adaptor 80 of FIGS. 12 to 17 has a housing formed from two connected halves 80a and 80b, shaped to one another, and possesses at least two levershaped current conductors 82 which are dependent upon locking parts 81 which fix the adaptor according to position in the current distriubtor rail 11, and are movable in opposite directions to and fro within the current distributor rail width; each current conductor 82 of the adaptor 80 possesses an outer contact part 83 which is contact-closable with an electrical conductor 13 of the current distributor rail 11, and is mounted in the adaptor housing, and also possesses an currentcarrying part 84 mounted inside the adaptor housing, after the contact closure between adaptor contact part 83 and rail current conductor 13 formed with a delay and suddenly contacting inner contact bridge 85, which is designed to be liftable from the current-carrying part 84 upon releasing the adaptor rapidly before the contact breakage between current distributor rail conductor 13 and outer adaptor contact part 83.

Each lever-shaped current conductor 82, with its end which is turned away from the current supply part 84, is held movably in the adaptor housing by means of a fastening screw 86, and is equipped with a plate-shaped contact part 83 which lies with the plane of the plate in the pivotal plane.

Between the current conductor pivotal point 86 and the contact part 83 the current conductor 82 possesses a lever-shaped contact bridge 85, which moves freely with the end adjacent to the contact part, and is in itself flexible in design, and which is shaped out from the lever-shaped current conductor 82, and with its other end stands in firm connection with the current conductor 82.

A spring 87, arranged between current conductor pivotal point 86 and the connection region between contact bridge 85 and currentconductor lever 82, holds the current conductor 82 in its switch-off position lying outside the adaptor housing, or endeavours to move this current conductor 13 towards the breadthbisecting ends of the adaptor housing so that the contact part 83 is pressed into the housing.

The contact bridge 85, at is freely-moving end, has a silver contact 88, which is contact-closable with the current supply part 84 and which is brought in contact with the current supply part 84.

The current-supply part 84 is fastened detachably by means of a fastening screw 89, to the housing half 80a and 80b; each current supply part 84 possesses at one end a contact tab 90 for the contact bridge 85, and has at its other end a screwless terminal 91 for one phase 92a of an electrical line 92.

To a shaft 93 which is immovably connected to an adaptor locking part 81, is fastened immovably a pressure body 94 which is equipped with two facing pressure surfaces 94a for two facing current conductor levers 82, and a switch lug which possesses two facing pressure surfaces 95a for the two facing contact bridges 85; the pressure surfaces 94a and 95a of the pressure body 94 and of the switch lug 96 are curved (arched in convex manner) in design, and lie on a common diameter. The switch lug pressure surface 95a has a smaller curve length than the pressure surface 94a of the pressure body, and in the direction of rotation of the shaft for the purpose of the electrical and mechanical locking of the adaptor in the current rail 11 isprovided at a spacing for the beginning and end of the pressure surface 940 of the pressure body, so that the pressure surface 94a acts first, and during its action, inserts the pressure surface 95a, and also before the end of this action again exposes the pressure surface 95a.

The contact bridge 85, in the central top region of the current conductor 82, is formed from the latter, and the switch lug 95 extends between two pressure surfaces 94a of the pressure body 94, which surfaces are provided one on top of the other.

On that side of the contact bridge which cooperates with the switch body pressure surface a, the bridge shows a stud 96, which makes possible a rapid moving-back of the switch bridge 85 out of the contact position into the switch-off position, which stud cooperates with the pressure surface 95a, presses the contact bridge 85 outwards, and upon passing of the pres sure surface 95a through the contact bridge 85 which is in itself flexible in design, permits a rapid springingback of the contact bridge 85.

In the adaptor housing is arranged at least one insulation part 98 which is held detachably by means of bars 97, which are on the side of the housing, the insulation part having a screw connection part 99 for a protective conductor 92b of the electrical line 92. The screw 99a of this screw connection 99 stands in contact with an earthing plate 100 which is held at the top in the adaptor housing, and upon insertion of the adaptor into the current distributor rail 11, comes into contact'with at least one protective conductor of the current distributor rail 11, before the earthing plate 100, inserted in grooves of the adaptor housing, is fixed simultaneously according to position in the adaptor housing by the screw connection screw 99a (compare FIG. 14).

The locking part 81 for fixing the adaptor is formed from'a plate pointed at right angles to the shaft 93 having two facing locking regions which project on both sides over the adaptor breadth and engage in clamping manner in facing grooves 17 of the current distributor rail 11.

The electrical and mechanical locking of the adaptor 80 in the current distributor rail 11 takes place as follows.

In the unfastened position of the adaptor 80, its contact parts 83 lie securely in contact inside the adaptor housing, and the facing current conductors 82 are held by the pressure springs 87 in the pivoted-in position (compare FIG. 13); likewise the locking part 81 does not project with its locking regions across the breadth of the adaptor.

If the adaptor 80 is inserted into the current distributor rail 11, there immediately takes place contact closure between earthing plate 100 and protective conductor of the current rail 11. Now the shaft 93 is rotated in the direction of the arrow, and the pressure surfaces 94a of thepressure body 94 press against the two facing current conductor levers 82, and move them outwards against the spring force, so that the contact parts 83 emerge laterally from the housing and come into contact with the electrical conductors 13 of the current distributor railll likewise, the leaking regions emerge across the breadth of the adaptor, and engage in the rail grooves 17.

FIG. 15 shows a rotated position of the shaft 93 with a partly locked locking part 81 and with contact parts 83 which stand in contact with the electrical lines 13;

the contact parts 83 are, however, still currentless, and the contact bridges 85 do not yet form contact with the current supply part 84.

If the shaft 93 is now rotated further in the direction of the arrow, the pressure surfaces 95a of the switch lug 95 act upon the projections 96 of the contact bridges 85, and press these with their silver rivet 88 against the current supply parts 84 now the contact parts 83 are current-carrying, and the adaptor is electrically and mechanically locked (compare FIG. 16).

If the flow of current is to be discontinued, and the adaptor 80 again removed from the rail 11, the shaft 93 is rotated further in the direction of the arrow; thereby the pressure surfaces 950 of the switch lug 95 slide off from the projections 96, and the contact bridges 85, flexible in themselves, can be rebound suddenly in the direction of the adaptor length-bisecting ends, so that the closure between current guide part 84 and contact bridge 85 and consequently contact part 83 is suddenly discontinued (compare FIG. 17). The shaft 93 is rotated further, and the pressure surfaces 94a of the pressure body 94 then release the current conductors 82 so that the latter can pivot towards each other through the spring force (towards the adaptor length-bisecting ends), and thereby take the contact parts 83 with them into the adaptor housing. Simultaneously, the locking regions reach out of the rail grooves 17, and the adaptor can be taken out of the current distributor rail 11. For rotating the shaft, the latter has on that end of the shaft situated in the lower region of the housing, a slot 93a for the inserting of a tool or a coin.

The adaptor 80 represented in the drawing is designed as a feeding adaptor, and for this purpose has the current conductors 82 arranged opposite one another and on top of one another in one end region, and posssesses in the other end region a bottom-sided, front-sided or top-sided introduction aperture 101 for the electrical lead 92, as well as a tension reliever 102 inside the housing.

This adaptor 80 can also be designed as a bridging adaptor for butting current rails 11, and as a supply adaptor; for this purpose there are arranged in both housing end regions, current conductors 82 which face one another and are arranged on top of one another (the adaptor half shown in FIGS. to 17 is duplicated), and the supply of current through the electrical lead 92 is omitted. The adaptor receives the supply of current from the current distributor rail 11.

In the case of a supply adaptor, the latter possesses at the bottom a connection piece 103 for a collector for a light, electrical appliance or the like.

In order to provide accurate polarisation, the adaptor housing, on one longitudinal edge of the housing which engages in the current distributor rail 11, is equipped with a chamfer 104, which co-operates with a corresponding surface of the current distributor rail 11, and allows insertion of the adaptor into the rail 11 in only one position.

The adaptor 105 represented in a further embodibody, and each switch body 108 is pivotable about an axis 109 which runs obliquely to the plane of movement of the contact part.

The two switch bodies which hold two facing contact parts 106 lie in movement surfaces 108a against one another, and are pivoted independence upon one another by a common switch shaft 111 which is immovably connected to a locking part 110. The switch shaft 111 is equipped with two facing switch lugs 112, which permit a rotation of the shaft 111 only in one direction. This adaptor is a supply adaptor, and in one end region has four contact parts 106, two of which are in each case arranged on top of one another and two beside one another; for the two contact parts 106, provided in each case beside one another, there are provided in each case two co-operating switch bodies 108, so that the adaptor 105 has four pivotable switch bodies 108 in the region of the contact parts 106.

A switch body 108 of the two co-operating bodies 108 is arranged between the switch shaft 111 and the other switch body 108, and is connected in springoperated manner to both parts 108 and 111.

Between the contact parts 106 and the switch bodies 108 there extends a pressure element 113 which is supported on the wall of the housing half, and which acts upon the lever 107, by a pressure spring which endeavours to bring the contact parts 106 into the housing into the switch-off position.

A current supply part 114, mounted in the adaptor housing for each contact part 106, stands with one end in sliding contact with the lever 107, and engages in the switch body 108, and butts in sliding manner against the lever 107. The other end of the current supply part 114 butts against a rotatably mounted selector organ 115 which is equipped with a collector part 1 16, which is connectable with one of the contact parts 106 arranged in the adaptor 105, for the purpose of determination of the circuit.

This selector organ 115 is formed from a cylindrical part having arranged in it a collector part 1 16 which is exposed on the jacket side.

Of the four current supply parts 114, three butt against the selector organ 115, and one of them is connected as a current-supplying conductor to the collector part 116, as desired, so that one of the three conductors 114 supplies current (position 1, 2 and 3).

The fourth current supply part 114 forms a neutral conductor which is led via an electrical lead 117 to a coupling 118 arranged below the selector organ.

The selector organ 115 lies accessible at the top in the adaptor 105, and possesses a rotation slot 119 for adjusting the rotary position. The connection between collector part 116 and one of the three currentsupplying conductors 114 takes place before the insertion of the adaptor 105 into the currrent distributor rail 11. As the selector organ 115, in the case of an adaptor 105 lying inside the rail 11 can no longer be rotated, disturbances (through alteration of the circuit) are precluded.

- An electrical lead 120 is led from the collector part 116 to the connection part 118. In the upper region of the adaptor 105 extends an earthing plate 121 which comes in contact with the protective conductor 15 of the rail 11, before the electrical current closure, upon inserting of the adaptor 105 into the current distributor rail 11, which earthing plate is connected to an electrical lead 122 likewise led to the connection piece 118;

the electrical leads 117, 120 and 122 are fixed in screwless terminals 123 of the connection piece 118.

The two locking parts 110 which are rotatably mounted in each case with a bearing lug 124 in the bottom walls of the housing halves 105a and 105b extend in longitudinal direction of the housing on both sides of the selector organ 115, and are secured in their rotated positions against undesired movement, through a spring 126 which is fixed at one end below the locking part 110 in the lug 124, and which catches with the other free end in recesses 125 of the housing bore-hole which accepts rotatably the lug 124(compare FIGS. 18 and 19).

For rotation of the locking parts 110, their lug 124 shows in each case one insertion slot 127 for a coin or the like.

The electrical and mechanical locking of the adaptor 105 in the current distributor rail 11 takes place as follows.

Before inserting the adaptor 105 into the rail 11, the selector organ 115 is rotated and one of the three current supply parts 114 is connected as a current-supply conductor to the collector part 1 16. If the adaptor 105 is inserted in the rail 11, its two locking part lugs 124 are rotated which results simultaneously in a rotation of the switch shaft 111 of one locking part 110. The locking parts 110 project out over the sides of the adaptor, and are jammed in the grooves 17 of the rail 11, so that the mechanical locking (fixing of the adaptor) is accomplished.

Upon rotation ofthe switch shaft in the direction of the arrow, this shaft presses with one of its lugs 112 against a switch body 108, which is pivoted about its axis 109, and thereby presses against the other switch body 108, and likewise pivots this about its axis 109. Through the pivoting of both'switch bodies 108, the contact parts 106 are moved via their lever 107 against the spring 113 outwards of the adaptor 105, and achieve contact with the current conductors 13 of the rail 11. v

If the adaptor. 105 is to be released from the rail 11, the lugs 24 are further rotated in the same direction, so that the switch shaft 111 is also further rotated in the direction of the arrow; the lug 112 thereby suddenly slides off from the adjacent switch body 108, and the two springs 113 press the facing contact parts 106, through the release of the two co-operating switch bodies 108, rapidly into the housing, and the electrical contact between contact parts 106 and rail current conductors 13 is discontinued.

Simultaneously, the locking parts 1 10 are rotated out of the grooves 17 of the rail 11, and the adaptor 105 can be removed.

In order to avoid formation of an are between adaptor current conductor 106 and rail current conductor 13 upon releasing the adaptor 105, and to achieve the electrical switching on and off inside the adaptor 105,

the current-carrying parts 114 are divided into the two exemplified embodiments according to FIGS. 21 and 22, and formed from a part 128 which stands in contact with the contact lever 107, and a part 129 which butts against the selector organ 115, and which are closable with one another by a connection contact 130 and 131 of a slide block 132 which is movable in dependence upon the rotation of the switch shaft. This slide block 132 is mounted shiftably in guides 133 in the adaptor housing, and is held in the switch-off position or brought into this position by a spring 134.

In accordance with FIG. 21, each connection contact is held pivotably on the current-carrying part 128 with a bar 1300 standingin contact with the currentcarrying part 128, and is pivoted by a co-ordinated bevel surface 132a of the slide block 132 about this bar 1301, and thereby brought in contact with other current-carrying part 129, or broken in its contact.

The connection contact 130 represents a pivotable contact bridge. In the top half of the drawing FIG. 21 this is pivoted into the switch-off position, and in the bottom half has been brought into the connection position.

In the case of the embodiment according to FIG. 22, each connection contact 131 is mounted as a contact bridge in pendulum fashion on the slide block 132, and connect the ends of the two contact parts 128 and 129, which ends are provided at a spacing to one another; the pendulum-type mounting of the connection contact 131 ensures automatic and safe placing of the contact 131 against the contact parts 128 and 129. The top half of FIG. 22 shows the connection contact 131 in the switched-off state, and the bottom half of the drawing represents the switched-on state.

The spring 134, upon sliding down of the lug 112 from the slide block lug 135, presses the slide block 132 rapidly out of the connection region, avoiding arc formation.

I claim:

1. In a current-distributing system, an elongated current distributor rail of channel-shaped cross section having a hollow interior and a pair of opposed side walls, said rail carrying at its side walls a plurality of current-supplying conductors which are accessible from the interior of said rail and the latter also carrying an elongated ground conductor which is accessible at the interior of the rail, said side walls being formed at the interior of said rail with longitudinally extending locking grooves, and an adaptor insertable into and movable longitudinallyalong the interior of said current distributor rail, said adaptor having an elongated hollow housing adapted to be situated within and extend along the interior of said rail and having opposed side walls formed with openings passing therethrough and aligned respectively with said current-supplying conductors and with said locking grooves, said adaptor housing carrying at its exterior a springy ground connector which engages said ground conductor accessible at the interior of said rail when said adaptor housing is introduced into said rail, releasable lock means carried by said housing in the interior thereof for movement between an unlocking position situated entirely within said housing and a locking-position extending through openings in said side wall of said housing into said loc'king grooves, a plurality of contact-carrying levers swingably mounted in the interior of said housing, said levers respectively carrying contacts which project from said levers in alignment with openings of said housing walls which are aligned with said currentsupplying conductors when said adaptor is in said rail, cam means carrried by said adaptor housing and extending to the exterior thereof so as to be operable from the exterior of said adaptor housing, said cam means operatively engaging said contact-carrying levers as well as said lock means for displacing said lock means into said locking grooves for locking said housing in said rail and also for swinging said contactcarrying levers to displace said contacts through openings of said adaptor housing into engagement with said current-supplying conductors, said cam means having a configuration which releases said levers for free movement independently of said cam means in a direction displacing said contacts into said housing out of engagement with said current-supplying conductors when said cam means is operated to disconnect said contacts from said current-supplying conductors, and a plurality of spring means carried by said housing in the interior thereof and operatively engaging said contact-carrying levers for quickly swinging the latter in a direction displacing said contacts away from said current-supplying conductors when said cam means is operated to release said levers for free swinging movement in the direction which displaces said contacts away from said current-supplying conductors, whereby arcing during the swinging of said contact-carrying levers away from said current-supplying conductors is avoided. w

2. The combination of claim 1 and wherein said adaptor housing carries a manually operable selecting means for selecting those contaeOs which are to be connected into an electrical circuit, and a plurality of elongated conductors situated in said housing and extending from said selecting means to said levers for conducting current through the latter and the contacts carried thereby.

3. The combination of claim 2 and wherein said levers include bodies swingably mounted in said housing with the body of one lever engaging the body of a second lever for transmitting swinging movement from said on lever to said second lever, said cam means engaging only said body of said one lever and having the configuration which restricts said cam means to only one direction of rotation.

4. The combination of claim 1 and wherein said adaptor housing carries in its interior plurality of elongated conductors respectively engaging said contactcarrying levers for completing a circuit therewith, the latter elongated conductors each including a pair of spaced portions situated in said adaptor housing, and bridging means activated by said cam means for bridging the space between said spaced portions of each of the latter elongated conductors when said cam means is actuated to place said contacts in engagement with said current-supplying conductors, and additional spring means situated in said housing and coacting with said bridging mens for displacing the latter to a position where said bridging means no longer interconnects the spaced portions of each of said elongated conductors when said cam means is actuated to release said levers for movement in a direction displacing said contacts away levers for said current-supplying conductors.

5. The combination of claim 4 and wherein each of said bridging means is in the form of a swingable bridging lever swingably engaging one of said portions of each of said elongated conductors and a second cam means actuated by said first-mentioned cam means and tilting said bridging lever to electrically interconnect the spaced portions of each of said elongated conductors when said first-mentioned cam means is actuated to place said contacts in engagement with said currentsupplying conductors, said additional spring means acting on said second cam means for displacing the latter in a direction which swings said bridging levers to a location where they no longer electrically interconnect the spaced portions of said elongated conductors in the interior of said housing.

6. The combination of claim 4 and wherein said bridging means includes a second cam means actuated by said first-mentioned cam means and swingably car rying pendulum bridging members which bridge the space between and interconnect electrically the space portions of each of said elongated conductors when said first-mentioned cam means is moved to a position locating said contacts in engagement with said currentsupplying conductors, said second spring means displacing said second cam means to a position moving said pendulum bridging members away from the bridging positions thereof when said first-mentioned cam means is actuated to release said contact-carrying levers for movement in a direction displacing said contacts away from said current-supplying conductors.

7. The combination of claim 1 and wherein said spring means is in the form of a plurality of compressed coil springs situated between side walls of said housing and said contact-carrying levers for urging the latter inwardly toward the interior of said housing in a direction displacing said contacts inwardly away from said current-supplying conductors of said rail.

8. The combination of claim 1 and wherein said lock means, said contact-carrying levers and said cam means have with respect to each other a relationship according to which said lock means first extends into said locking grooves before said contacts engage said currenbsupplying conductors.

9. The combination of claim 1 and wherein each of said levers carries a springy elongated conductor portion urged by said cam means to a current-conducting position after said contacts engage said currentsupplying conductors.

10. The combination of claim 1 and wherein said spring means are in the form of toggle springs coacting with said levers for first snapping them outwardly to place said contacts in engagement with said currentinwardly for quickly displacing said contacts away from said current-supplying conductors. l i l k 

1. In a current-distributing system, an elongated current distributor rail of channel-shaped cross section having a hollow interior and a pair of opposed side walls, said rail carrying at its side walls a plurality of current-supplying conductors which are accessible from the interior of said rail and the latter also carrying an elongated ground conductor which is accessible at the interior of the rail, said side walls being formed at the interior of said rail with longitudinally extending locking grooves, and an adaptor insertable into and movable longitudinally along the interior of said current distributor rail, said adaptor having an elongated hollow housing adapted to be situated within and extend along the interior of said rail and having opposed side walls formed with openings passing therethrough and aligned respectively with said current-supplying conductors and with said locking grooves, said adaptor housing carrying at its exterior a springy ground connector which engages said ground conductor accessible at the interior of said rail when said adaptor housing is introduced into said rail, releasable lock means carried by said housing in the interior thereof for movement between an unlocking position situated entirely within said housing and a locking position extending through openings in said side wall of said housing into said locking grooves, a plurality of contact-carrying levers swingabLy mounted in the interior of said housing, said levers respectively carrying contacts which project from said levers in alignment with openings of said housing walls which are aligned with said current-supplying conductors when said adaptor is in said rail, cam means carrried by said adaptor housing and extending to the exterior thereof so as to be operable from the exterior of said adaptor housing, said cam means operatively engaging said contact-carrying levers as well as said lock means for displacing said lock means into said locking grooves for locking said housing in said rail and also for swinging said contact-carrying levers to displace said contacts through openings of said adaptor housing into engagement with said current-supplying conductors, said cam means having a configuration which releases said levers for free movement independently of said cam means in a direction displacing said contacts into said housing out of engagement with said current-supplying conductors when said cam means is operated to disconnect said contacts from said current-supplying conductors, and a plurality of spring means carried by said housing in the interior thereof and operatively engaging said contact-carrying levers for quickly swinging the latter in a direction displacing said contacts away from said currentsupplying conductors when said cam means is operated to release said levers for free swinging movement in the direction which displaces said contacts away from said current-supplying conductors, whereby arcing during the swinging of said contactcarrying levers away from said current-supplying conductors is avoided.
 2. The combination of claim 1 and wherein said adaptor housing carries a manually operable selecting means for selecting those contaeOs which are to be connected into an electrical circuit, and a plurality of elongated conductors situated in said housing and extending from said selecting means to said levers for conducting current through the latter and the contacts carried thereby.
 3. The combination of claim 2 and wherein said levers include bodies swingably mounted in said housing with the body of one lever engaging the body of a second lever for transmitting swinging movement from said on lever to said second lever, said cam means engaging only said body of said one lever and having the configuration which restricts said cam means to only one direction of rotation.
 4. The combination of claim 1 and wherein said adaptor housing carries in its interior plurality of elongated conductors respectively engaging said contact-carrying levers for completing a circuit therewith, the latter elongated conductors each including a pair of spaced portions situated in said adaptor housing, and bridging means activated by said cam means for bridging the space between said spaced portions of each of the latter elongated conductors when said cam means is actuated to place said contacts in engagement with said current-supplying conductors, and additional spring means situated in said housing and coacting with said bridging mens for displacing the latter to a position where said bridging means no longer interconnects the spaced portions of each of said elongated conductors when said cam means is actuated to release said levers for movement in a direction displacing said contacts away levers for said current-supplying conductors.
 5. The combination of claim 4 and wherein each of said bridging means is in the form of a swingable bridging lever swingably engaging one of said portions of each of said elongated conductors and a second cam means actuated by said first-mentioned cam means and tilting said bridging lever to electrically interconnect the spaced portions of each of said elongated conductors when said first-mentioned cam means is actuated to place said contacts in engagement with said current-supplying conductors, said additional spring means acting on said second cam means for displacing the latter in a direction which swings said bridging levers to a location where tHey no longer electrically interconnect the spaced portions of said elongated conductors in the interior of said housing.
 6. The combination of claim 4 and wherein said bridging means includes a second cam means actuated by said first-mentioned cam means and swingably carrying pendulum bridging members which bridge the space between and interconnect electrically the space portions of each of said elongated conductors when said first-mentioned cam means is moved to a position locating said contacts in engagement with said current-supplying conductors, said second spring means displacing said second cam means to a position moving said pendulum bridging members away from the bridging positions thereof when said first-mentioned cam means is actuated to release said contact-carrying levers for movement in a direction displacing said contacts away from said current-supplying conductors.
 7. The combination of claim 1 and wherein said spring means is in the form of a plurality of compressed coil springs situated between side walls of said housing and said contact-carrying levers for urging the latter inwardly toward the interior of said housing in a direction displacing said contacts inwardly away from said current-supplying conductors of said rail.
 8. The combination of claim 1 and wherein said lock means, said contact-carrying levers and said cam means have with respect to each other a relationship according to which said lock means first extends into said locking grooves before said contacts engage said current-supplying conductors.
 9. The combination of claim 1 and wherein each of said levers carries a springy elongated conductor portion urged by said cam means to a current-conducting position after said contacts engage said current-supplying conductors.
 10. The combination of claim 1 and wherein said spring means are in the form of toggle springs coacting with said levers for first snapping them outwardly to place said contacts in engagement with said current-supplying conductors and for then snapping said levers inwardly for quickly displacing said contacts away from said current-supplying conductors. 